Basal cell carcinoma (BCC) is the most common form of skin cancer and the most common form of cancer of any type in the United States. It develops in the basal germinative cell layer of the epidermis, often on sun-exposed areas of the skin. Although BCC rarely spreads (i.e., metastasizes) to other parts of the body, it can be very destructive and disfiguring. BCC may cause local tissue destruction that may lead to disfigurement or functional impairment of surrounding non-cancerous tissue. Disfigurement may be a particular concern of BCC patients because many BCC tumors occur on the sun-exposed—and, therefore, also typically otherwise exposed—skin of the head and neck. Larger tumors, tumors that have been present for long periods of time, and tumors that have recurred after initial therapy may be biologically more aggressive and especially difficult to cure. While the mortality rate of BCC is relatively low, its increasing incidence and prolonged morbidity means that the disease can be very costly to treat.
A wide variety of surgical and non-surgical therapies are available for BCC. Nonsurgical therapies include radiation therapy, chemotherapy, and immunotherapy. These therapies can be useful for definitive treatment of primary tumors and some recurrent BCC tumors and for relieving symptoms associated with inoperable tumors. However, some of these therapies also can have significant unpleasant side effects. Side effects of radiation therapy and certain chemotherapies are well documented. One form of immunotherapy involves intralesional injections of interferon. While interferon therapy can be effective against BCC, the multiple intralesional injections can require several clinic visits per week for many weeks. Also, many patients can be anxious or otherwise uncomfortable receiving injections. Thus, interferon therapy can result in significant patient inconvenience and discomfort.
Interferon therapy also is connected with several side effects such as, for example, flu-like symptoms such as fever, chills, aches, drowsiness and nausea; a reduction in the number of white blood cells; a reduction in the number of red blood cells (anemia); a reduction in the number of platelets in the blood, which may give rise to nosebleeds, for example; thinning hair; liver problems; and heart problems.
Surgical therapies include excision, curettage and electrosurgery, cryosurgery, Mohs micrographic surgery, and laser surgery. Excision is useful for both primary and recurrent tumors and has the advantage of allowing for histological assessment of surgical margins. Curettage and electrosurgery involves alternately removing soft tumor tissue with a curette and then destroying an extra margin of tissue by electrodesiccation, electrocautery, or electrocoagulation. The procedure may be repeated as necessary. Cryosurgery involves freezing the tumor to a temperature that kills the cells of the tumor. The dead tumor cells can be removed by, for example, curettage. Mohs micrographic surgery (MMS) involves a surgeon using a microscope to improve identify the margin of the tumor more accurately and more precisely than is possible by unaided visual inspection. MMS can increase the likelihood that the entire tumor is removed and minimize the amount of normal tissue that is removed. Laser surgery involves using a laser to vaporize tumor cells. Alternatively, the laser may be used in lieu of a scalpel blade for excisional surgery.